Astrology is a belief, a study of the positions of celestial bodies. Celestial bodies have cosmic influence on biotic and abiotic bodies on our planet Earth. Astrology can provide information about personality, human affairs and other "earthly" matters based on the relative positions of celestial bodies and related details.
A group of seven celestial bodies which influence human affairs and personalities are divided into 12 signs. The seven day system is based on the ancient astrological perceptions that the seven celestial bodies influence what happens on Earth and that each of these celestial bodies control the first hour of the day name after it.
Astrology is different from astronomy. Astronomy is the study of objects and phenomena beyond the Earth's atmosphere, is a science and is a widely studied academic discipline. Astrology on the other hand uses the apparent positions of celestial objects as the basis for psychology, prediction of future events, and other esoteric knowledge.
Numerous traditions and applications employing astrological concepts exist today. Early astrology like Vedic astrology has played an important role in the shaping of culture and various disciplines throughout history.
Jyotish ( ज्योतिष ) is a traditional astrology of Indian subcontinent, has been mentioned as the sixth limb of the Vedas in the ancient Vedanga Jyotisha. As mentioned in Upanishads, there are six Vedangas: Shiksha, Kalpa, Vyakarana, Jyotishya, Nirukta and Chhandas. Seven celestial bodies along with two shadow planets Rahu and Ketu are called Navagrahas of Astrology.